Transfer printing mechanism



Jan. 3, 1956 1.. M. STEMPEL TRANSFER PRINTING MECHANISM 2 Sheets-Sheet 1Filed June 17, 1948 m Ta m W m m u a L man/ 2 42, QM $M ATTORNEYS Jan.3, 1956 L. M. STEMPEL 2,729,164

TRANSFER PRINTING MECHANISM Filed June 17, 1948 2 Sheets-Sheet 2INVENTOR; Lasz/o M S/empe/ ATTORNEYS United States Patent 2,729,164TRANSFER PRINTING MECHANISM Laszlo M. Stempel, New York, N. Y., assignorto Laszlo M. Stempel, New York, and Albert Charles Nolte,

Plandome, N. Y., as joint trustees Application June 17, 1948, Serial No.33,636 1 Claim. (Cl. 101415.1)

The present invention relates to transfer cylinders for applying aprinted or lithographed impression to a web of paper or other material.

More particularly, the invention relates to means for.

securing and tensioning a flexible transfer blanket which is wrappedaround the periphery of the cylinder.

Arrangements for the tensioning of flexible transfer blankets are knownin the art, and these generally teach the fastening of one end of theblanket within a slot in the cylinder. The free end is then drawn intothe cylinder slot adjacent to the end which is already secured therein.Such tensioning arrangements have the effect of tightening the transferblanket about the circumference of the cylinder by means of tensionapplied to only one end of the blanket. Because of frictional forcesbetween the inner surface of the blanket and the periphery of thetransfer cylinder, there is a tendency toward eccentricity resultingfrom non-uniformity of the circumferential tension forces in theflexible transfer blanket.

Accordingly, it is an object of the invention to provide a transferblanket fastening arrangement in which the tension is appliedsubstantially equally to both ends of the transfer blanket.

A further object of the invention is to provide a recess in the transfercylinder adapted to receive the tensioning devices for both ends of thetransfer blanket and which will render a minimum portion of the cylindercircumference unusable for printing purposes.

Still another object of the invention is to provide fastening andtensioning members adapted to fit Within a recess in the cylinder andwhich will effectively close the recess when the blanket is tensionedabout the circumference of the cylinder.

Other and further objects will become apparent upon reading thefollowing specification together with the accompanying drawing forming apart hereof.

Referring to the drawing, Fig. 1 represents an enlarged sectional viewof a cylinder embodying the invention taken along the line 11 of Fig. 4,looking in the direction of the arrows;

Fig. 2 is a similar view Fig. 4 some of the tion;

Fig. 3 is a view similar to Fig. 1;

Fig. 4 shows a view in sectional elevation, partly broken away, of atransfer cylinder embodying the invention, the section shown at the lefthand portion of Fig. 4 being taken along the line 44 of Fig. 1;

Fig. 5 shows a view in elevation of an eccentric collar member used inpracticing the invention;

Fig. 6 is a sectional view taken along the line 1-1 of Fig. 4 with thetransfer blanket and tensioning members omitted;

Fig. 7 is a transverse sectional view showing a modified form oftransfer cylinder and blanket with the blanket partially applied;

Fig. 8 is a view similar to Fig. 7 but showing both taken along the line2-2 of parts being shown in a different posimember 14 may first be2,729,1(54 Patented Jan. 3, 1956 2 blanket clamps lodged in the cylinderrecess and the collars turned to a retaining position;

Fig. 9 is a view similar to Fig. 8 but showing the collars turned stillfurther to retain the blanket clamps in positions such that the blanketwill be held taut; and

Fig. 10 is a sectional view similar to Fig. 4, the view being taken upthe line 10-10 of Fig. 9 looking in the direction of the arrows.

Referring to Fig. 1, a transfer cylinder 11 is provided with alongitudinal slot 12 adapted to receive a pair of bar members 13 and 14.Slot 12 is so shaped that bar inserted within the slot and pushed to oneside as shown in Fig. 2, and the bar member 13 may then be inserted.Collars 15 and 15' are provided with eccentric recesses 16 and 16 andwith apertures 17 and 17. The protruding ends of bar members 13 and 14are inserted into the recesses 16 and 16' through the apertures 17 and17. Each of the collars 15 and 15' is shown made in two sections securedtogether by bolts 18 which serve to assemble each collar with capacityfor free rotation upon a neck portion 19 of cylinder 11.

The cylinder 11 is shown with extending shaft portions 20 journalled insuitable bearings 21, the bearings being supported by side walls 22 ofthe printing press or other machine. Suitable provision is made fordriving the transfer cylinder and for bringing it into engagement withthe printing plate and with the web of material to be printed. Thesefacilities are well known in the art and may take any desired form.

' Each bar member is provided with extending end portions adapted forengagement with the walls of the respective eccentric recesses 16 and 16of collar members 1'5 and 15'. On bar member 13, these projections aredesignated 23 and 23', and on bar member 14 they are designated 24 and24. A transfer blanket 25 is provided at each end with a plurality ofholes, spaced to conform to the spacing of screws 26 which clamp each ofthe two ends of the blanket between one of the bar members and one ofthe auxiliary clamping bars 27 and 28 associated with bar members 13 and14 respectively.

In operation, the two ends of transfer blanket 25 are secured to the barmembers 13 and 14 by means of auxiliary clamping members 27 and 28 andbar member 14 is first inserted within slot 12. Thereafter, the bar Amember 13 is inserted within displacing the bar member 14 so that it isretained within the internal recess formed by the over-hanging shoulderof slot 12. This can best be seen in Fig. 2.

Bar member 13 is then pressed downwardly into the remaining space inslot 12, the upwardly extending portion 30 thereof filling the remainingopening of the slot. At the time that the bars are inserted within slot12, the openings 17 and 17' in eccentric collars 15 and 15' arepositioned to permit passage of the protruding ends of the bar members.After these end portions have been passed through openings 17 and 17 andthus been brought within the eccentric recesses 16 and 16 the essentriccollars 15 and 15 are then rotated substantially equally to draw bothbar members radially inwardly within the slot 12 toward the center ofcylinder 11, thereby drawing the transfer blanket 25 snugly around theperiphery of cylinder 11 with a tension which is substantially evenlyapplied at both ends of the blanket. Unevenness in tension along the barmembers 13 and 14 may be equalized by separate rotation of one of theeccentric collars 15 or 15'.

In Fig. 1 the eccentric collars 15 and 15' have been rotated to draw theblanket 25 around cylinder 11 and lock bars 13 and 14 within slot 12.

In Fig. 3 the eccentric collars 15 and 15' have been turned further toapply a tension to the blanket 25,

slot 12 after first laterally ing ends 23, 23' and 24, 24'- and theinternal surfaces of recesses 16 and 16' are sufiicient to. retain thecollars 15 and 15" in the position indicated in Fig.- 3' in whichtensionis maintained on the: blanket 25'.-

When it isv desired to withdraw the bars from the recess 12 of thecylinder 11, the bar 18*, if jammed, canbe'loosened'or dislodged by theuseof a heavy screw driver or any other tool suitable foruse as a pry orlever: The inner edges 13x of the barl?!- and145r of the. bar 14. areinclined away from the cylinder axis at the ends-as seen in Fig. 4.Notches 12x are provided atthe' ends of the cylinder 11" to enable alever to be inserted beneaththe edges 13x of the bar 13and"14ir ofthebar'lqi.

In Figs. 7 to 10; inclusive, disclosure is made of a further embodimentofthe invention. As before, a transfer, cylinder 11a is. surrounded by aflexible transfer blanket. 2521. The cylinder is mounted through bearingportions 20a in bearings. 21a, the latter being supported in sid'eframemembers 22a.

The cylinder 11a is formed' with a longitudinally extending: recess 41.The recess 41 includes a relatively narrow entrance. portion, throughthe periphery of the cylinder, a portion which can be entered directlythrough. theentrance portion, and an offset, undercut portion, thetwotlatter portions being merged and havnig substantially radial,parallelwalls.

The ends-of. the blanket25'a are, secured by clamps as.

before, but,the clamps are somewhat modified inform,

as compared with the structures illustrated in. Figs. 1 to 4. The firstclamp 42 comprises a main bar 43 which is lodged in. the undercutportion of the recess 41 and an. auxiliary, bar 44 which engages theopposite face ofv the,

blanket 25a; Headed screws 45 have their bodies passed,

through: the auxiliary bar 44 and threaded into the main. bar 43.- Themain and auxiliary bars are both plain rectangularbars, and the ends ofthe bar 43 do not extend beyond the ends ofthe cylinder 11a.

The second clamp comprises a main bar 46, and an auxiliary bar 47.Headed screws 48 have. their bodies passed through, the auxiliary bar 47and. threaded into the bar 46.- The bar146 is-formed with a shoulderedrabbet 49.- which is adapted to be driven downinto position to receiveand engage the auxiliary bar 44 of the first clamp.

Initially the bar 43 may notlie sq uarely. in the undercu portion of therecess as shown in Fig. 7 but may'extend obliquely across the recess. Asthe second clamp, is

driven down into the recess, a-camv surface 50. at the lower,

inner. corner of the clamp plate 46 engages thev auxiliary clamp plate44, and earns it aside so as to cause the plate 44 to become located invthe rabbet. The combined thickness of the clamps is substantially equal.to the width of the recess 41, there being just enough clearance to per-4 mit. the clamps.v to. slide. snugly. relatively. to. the, cylinder.and to one another.

The plate 46 is formed with protruding ends 51 which cooperate with camsleeves 15a in the manner already described with reference to Figs. 1 to5. The construction of the cam sleeves issprecisely the same asillustrated in Fig. 5.

The clamp'plate 46 has" a notch or groove-52 formed inits. outer. face.With: this. construction. a. suitable; tool, such as a coldchisel may;be used for-drivingihe plate 46 down into the recess, 41 the edge of thechisel; being lodged in the, groove. When the plate 46 has beendriven infar enough to cause the shoulder of the-rabbet 49 to engage the plate44, the, two clnmpsarepthereafter driven inward in unison so that theblanket is tensioned equally at its opposite ends. The cam collars 15aare turned to over-lie the protruding ends 51 of the plate 46 to holdthe plateagainst: retractiont This causes both clamps to be' heldin-blanket tensioningpositions.

I have described what I believe to be the best-'embodie mentsoii'myinventiom I do notwish, however, to be confined to the embodimentsshown, but what L desire to cover by Itetters Patent isset forth intheappended claim.

I claim:

In a transfer press, in combination, a transfer cylinderhaving alongitudinal recess formed therein, the recess including a relativelynarrow entrance portion through the-pheriphery: ofthe cylinder, aportion which canbe entered directly through the entrance portion, andan offset undercut portion, the two latter portions being merged andhaving substantially radial, parallel walls, a flexible blanket wrappedaround the periphery of the cylinder, blanket clamps secured to'theopposite ends'of the blanket and: each including a main bar and anauxiliary bar, the main bar of the first clamp'being lodged intheundercut portion, of the recess, and the. main bar of. thesecond clampbeing formed with a shouldered rabbet in which the auxiliary bar 05 thefirst clamp is received, the clamps being of a combined thicknesssubstantially to fill the width of the recess, the second clamp asit isforced inward: into the recess serving to: force the first clampinward-alsmthetmain bar of the secondclamp-being formed with:protruding: ends, and: retaining members cooperative with said ends tocause bothclamps to beheld in blanket tensioning positions.

References Cited inthe file. of. thispatent UNITED" STATES PrYlElN'lTS

